anonymous - Computer Definition

Computer crackers commonly attempt to exploit a
computer system by sending messages in an anonymous fashion—protecting their
identity from being disclosed. Anonymous accounts are used widely to access
information and software-sharing systems on computers mainly using the FTP. The user accesses the systems by
utilizing a user name of “anonymous” or “guest” without a password.

(2) (Anonymous) A loose, underground hacker community that attempts to bring down or damage Web sites of organizations and government agencies that are not socially responsible. Advocating freedom, fairness and justice, Anonymous became known to the public in a 2007 Los Angeles TV report and has since claimed responsibility for numerous break-ins. In 2010, it hacked PayPal, MasterCard and Visa for no longer accepting donations to WikiLeaks after the site disclosed U.S. military documents. See WikiLeaks.
The Guy Fawkes Mask
Anonymous adopted a mask created to honor Guy Fawkes as a symbol of rebellion in the 2005 movie "V for Vendetta." Fawkes was in charge of the gunpowder in a failed 1605 plot to blow up Parliament and restore a Catholic monarchy to England. About to be hanged to near death and then disemboweled, Fawkes jumped from the gallows and did himself in. In 1606, Parliament turned the foiled Gunpowder Plot into a national holiday.

Anonymous "Reconnect" Rally

In Amsterdam in 2008, Anonymous objected to Scientology ordering its members to "disconnect" with anyone not supportive of their beliefs. (Image courtesy of photographer John Melskens.)